Re: Need tips on welding aluminium..
You're still using the buzz-box, right?
You can only weld AL with DC, not AC. And even at that, it is quite difficult, because it takes the heat away so fast. You've got to preheat, get the temp just right, keep it there, and weld. It is VERY VERY difficult. On an airplane, there are no welds that are not critical. It is a bit different from a jeep--when you're 15,000' up, you don't want a single weld to break. And I'm not busting your chops--I certainly wouldn't want to weld AL for an airplane myself, especially with a buzzbox.